Link A Button To Open A Form In Ms Visual Studio 11 Developer Preview?

I am developing a next gen App for my Email Client for future Windows 8 users. Now when i used to use Visual Studio (Visual Basic) 2008 to develop for Windows 7, I used the command "FORMNAME.show()" And that command would open the form.The Problem i am having now is that "SHOW" is not included and im guessing that there has to be another way to do this. For the Beta version of my app, i created a test Button that i want to open a "SplitPage1" the button is called " btnOpen"?Now to give you an idea what i wanna do, i made buttons on the top right hand corner that are called "File , Edit , View" and so on, and when the user clicks file, i want a spiltpage to open with all the options the user would regularly have when clicking file on a menu tab in a program. the options would be lined up on the left hand side when you hover over lets say "New Email" on the right hand side there will be a short description that will appear saying "create a new email to send" and when clicked on it will take the user back to the mainPage and it redirect the browser to "SendnewEmail url".